RU2459094C1 - Two-stroke internal combustion engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: two-stroke internal combustion engine includes the cylinder in the wall of which there made is scavenging and discharge openings and piston with fire-resistant insert at the bottom, which is kinematically connected to crankshaft, and injector; according to the invention, and in head of working cylinder there installed is insert from heat-resistant material with low heat conductivity, in which combustion chamber of cylindrical shape is made; ratio of diameter of combustion chamber to its length is within 0.1-0.15; fuel injector is placed in combustion chamber end face, and a gap between cylinder head and piston in position of upper dead point is 0.8-1.0% of the piston travel value.

EFFECT: increasing compression degree and increasing the efficiency.

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Description

The invention relates to the field of engineering and is intended for use in engine building.

Known is a two-stroke internal combustion engine containing a working cylinder, in the wall of which purge and exhaust windows are made, with a piston placed in it and connected to the crankshaft via a connecting rod, in which the crankcase is sealed by a supercharger: motorcycle engines, chainsaw engines, trimmers etc. (see book. M.P. Isaev, V.A. Zabelin. "Motorcycles IZH-56 and IZH-Jupiter." Udmurt Book Publishing House, Izhevsk. 1961, pp. 14-16).

A known two-stroke diesel engine containing a working cylinder, in the wall of which there are purge and exhaust windows, with two pistons placed kinematically connected in it and moving in opposite directions are diesel engines of the type 2D100, 10D100 (Prince A.I. Volodin. " Locomotive internal combustion engines ”, Moscow,“ Transport ”, 1990, cc.l7-21).

Known is a two-stroke internal combustion engine containing a working cylinder, in the wall of which purge and exhaust windows are made, with a piston placed in it kinematically connected to the crankshaft through a connecting rod, and a supercharger cylinder in the wall of which are made inlet windows with a piston placed in it, kinematically associated with the crankshaft with a phase offset relative to the piston of the working cylinder 180 ° (see application UK No. 2020738, IPC F02B 33/02, 1979). Adopted as a prototype.

The efficiency of these engines does not reach 40%, while theoretically they can reach from 70 to 80%.

The reasons that impede the achievement of the required technical result when using the prototype include the fact that the compression ratio in modern engines is limited by the insufficient heat resistance of the combustion chamber.

The invention is as follows. The problem to which the invention is directed, is to maximize the efficiency of the engine.

This problem is solved by achieving a technical result in the implementation of the invention, which consists in providing the possibility of increasing the degree of compression and, therefore, increasing the temperature of the combustion of the working mixture in the combustion chamber.

The specified technical result in the implementation of the invention is achieved by the fact that the two-stroke internal combustion engine contains a working cylinder, in the wall of which there are purge and exhaust windows, in the cavity of which a working piston is installed having a heat-resistant insert with low heat conductivity and a supercharger. An insert of heat-resistant material with low thermal conductivity is placed in the head of the working cylinder, in which a cylindrical combustion chamber is made, the ratio of the diameter of which to its length is in the range from 0.1 to 0.15. At the end of the combustion chamber is placed a fuel nozzle with one hole for fuel injection directed along the axis of the combustion chamber. In the TDC position, between the bottom of the piston and the cylinder head there is a gap of 0.8 to 1.0% of the piston stroke.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, and the identification of sources containing information about analogues of the claimed invention, allow us to conclude that no analogue was found with features identical to those of the claimed invention.

The definition from the list of identified analogues of the prototype, as the closest in purpose and combination of essential features, allowed to identify significant distinguishing features in relation to the invention achieved by the technical result set forth in the claims.

Therefore, the claimed device meets the condition of "novelty."

An additional search for known technical solutions showed that the claimed invention does not follow explicitly from the prior art for a specialist, since the effect of the transformations provided for by the essential features of the claimed invention on the achievement of a technical result has not been established from the prior art determined by the applicant.

Therefore, the claimed invention meets the condition of "inventive step".

The drawings depict the proposed engine. In Fig.1 - the extreme position of the piston during the cycle "purge", Fig.2 - the extreme position in the cycle "compression".

Information confirming the possibility of obtaining the above technical result is as follows.

A two-stroke internal combustion engine contains a working cylinder 1, in the head of which an insert 2 is made of a heat-resistant material with low thermal conductivity, for example, silicon carbide. A purge window 3 and an exhaust window 4 are made in the wall of the working cylinder 1. A piston 5 is placed in the cavity of the working cylinder 1. The piston 5 contains a ceramic heat-resistant insert 6 with low thermal conductivity, for example, silicon carbide. The piston 5 is connected to the crankshaft (not shown in the drawing) through a connecting rod 7. The engine also contains a supercharger 9 of any design, for example a centrifugal one with a mechanical drive, connected to a purge window 3 of the working cylinder 1. A fuel nozzle 8 is installed at the end of the cylinder 1. In the insert 2, a cylindrical combustion chamber 10 is made, the diameter of which is from 0.1 to 0.15 of its length. In the top dead center position, the gap between the piston and the cylinder head is from 0.8 to 1.0% of the piston stroke.

The engine operates as follows. After the flash of fuel supplied by the nozzle 8, when the piston 5 moves from the top dead center, a working stroke occurs. After the start of exhaust gas discharge through the window 4 in the working cylinder 1, the purge window 3 opens and the working fluid from the blower 9 through the window 9 enters the working cylinder 1, displacing the exhaust gases through the window 4. When the piston 5 moves further from the bottom dead center the purge window 3 and the exhaust window 4 are closed and the working fluid is compressed. Moreover, due to the presence of insert 2 of the working cylinder 1 and insert 6 of the piston 5, the compression ratio of the proposed engine is significantly greater than that of the prototype, and the combustion temperature can reach 1500 ° C, which provides higher engine efficiency compared to the prototype. Further movement of the piston 5 down (stroke) due to the presence of inserts 2 and 6 occurs adiabatically, with minimal heat loss. With further movement of the piston 5 from the bottom dead center, the purge window 3 and the outlet window 4 are closed and the working fluid is compressed.

Due to the fact that the combustion chamber 10 has an elongated cylindrical shape, and the nozzle 8 is located at its end, the combustion products remaining in the combustion chamber 10 after purging do not mix with the purge air oxygen during the compression stroke and are concentrated at the nozzle of the nozzle 8. The fuel stream during injection passes through this protective layer of combustion products that do not contain oxygen, and burns in the combustion chamber 10 outside the vicinity of the nozzle 8. In the gap between the insert 2 of the cylinder 1 and the piston 5, the fuel also practically does not get t, and the zone of extremely high temperatures does not reach the edge of the piston and cylinder walls.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed invention:

- a tool embodying the claimed invention in its implementation, is intended for use in industry for converting heat generated into mechanical work;

- for the claimed invention in the form described in the claims, the possibility of its implementation using the means described in the application is confirmed;

- a tool embodying the claimed invention in its implementation, is able to ensure the achievement of the perceived by the applicant technical result.

Therefore, the claimed invention meets the requirement of "industrial applicability".

Claims (1)

A two-stroke internal combustion engine comprising a cylinder, in the wall of which there are purge and exhaust windows, a piston with a heat-resistant insert in the bottom, kinematically connected with the crankshaft, and a supercharger, characterized in that an insert of heat-resistant material with low heat conductivity is placed in the head of the working cylinder, in which the combustion chamber is cylindrical in shape, the ratio of the diameter of the combustion chamber to its length is in the range from 0.1 to 0.15, a fuel nozzle is placed at the end of the combustion chamber, and the clearance m Between the cylinder head and the piston in the position of top dead center is from 0.8 to 1.0% of the stroke of the piston.

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